Storage-battery separator.



No. 693,676. Patented Feb. f6, |902. 4

6. M. w||.|.|s.

STORAGE BTTERY SEPHATOR.

(Application led Aug. 10, 1901.)

(Nu Model.)

@Q7-Morneau unica VNr GEORGE M. IVILLIS, OF CHICAGO, ILLINOIS.

STO RAG E-BATTERY S EPARATO R.

SPECIFICATION forming part of Letters Patent No. 693,676, dated February' 18, 1902. Application filed August l0, 1901. Serial No. 71,557. (No model.)

To @ZZ whom it may concern:

Be it known that I, GEORGE M. IVILLIS, a 'citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Storage-Battery Separatore, (Case No. 1,) of which the following is a full, clear, concise, and exact description, reference being had fo the accompanying drawings, forming a part of this specification.

My invention relates to storage batteries,

and has for its object the provision of an improved form of separator for maintaining the active material in the interstices provided in the plates or to maintain the active material that may be otherwise placed. A separator that would perform this function and at the same time maintain the resistance of the battery very low without short-circuiting its elements has been long sought for. The material that is best adapted for the purpose is glass-wool; butthe coefficient of friction between the fibers of this wool is so small that no denite relative disposition of the iibers can be made and retained unless the wool has been tightly packed between the assembled battery-plates in accordance with previous practice. This is undesirable in commercial practice for many reasons--for example, the fibers will break. Moreover, the battery-plates cannot readily be removed and replaced after the wool has been once packed in position.

Rubber bands have been proposed for fastening the wool in position, which had to be used, however, in combination with perforated sheets of suitable insulating material, as cardboard, the mass of glasswool being interposed between the cardboard and the batteryplate, the rubber bands surroundingthe elements thus assembled. The cardboard is essential, because the glass-wool has so much resiliency as to spring too far away from the battery-plate to permit the plate to be inserted in the place that is to receive the same, the cardboard serving to press the glass-wool to the proper thinness. The cardboard is readily decomposed and introduces considerable resistance and impedes the circulation of the battery fluid. It has also been proposed to employ threads of metal constituting the Warp of a fabric, in which fabric the glass constitutes the wool". This fabric is objectionable because of the great expense involved in its manufacture, because of the deterioration to which the lead, which is necessarily fine, is subject, and because of the liability of the threads of lead to short-circuit positive and negative plates. Lead however,was the only substance that would satisfactorily bind and maintain glass fibers together prior to my present invention.

I am enabled by means of myinvention to maintain the advantage arising from the use of glass-wool. The glass fibers of the wool may be of any length suited to the purpose, these fibers being bound together by the strings oriibers of the selected material, preferably non-metallic, or by other means or agency, to form the glass-wool into an unwoven fabric, of fibers matted together, which preferably is without stid backing. Where strings or threads are employed for forming the woolly mass into an unwoven fabric of fibers matted together, they are preferably disposedY as in quilting, being preferably arranged at right angles. The advantage of any binder that serves to maintain the glass liber in its matted state is that it enables the glass-wool to act as a very good filter, preventing the particles that may be detached from the plates from passing through the separators and collecting. I prefer, however, to employ as a binder some material that does not act as a conductor of current, the fabric thereby serving the additional function of a mechanical separator where necessary, or in any event preventing short-circuiting connection between adjacent plates. This binder of non conducting material is preferably made of asbestos, which for the purpose is formed into a thread that is sewed through the glass-wool. I believe that I am the first to successfully provide a thread of insulating material adapted to unite glass fibers to maintain the same in any desired shape. vThe glass is preferably a non-soluble silicate of potash, though I do not wish to be limited to the nature of the glass or glassy material entering into any embodiment of the invention. Asbestos is preferred as a binder, as it is plentiful and very flexible, the fibers being IOO very fine. The threads of asbestos or equivat lent material are passed among the glass fibers, preferably in a manner to greatly limit the amount of the thread brought into direct contact with the battery-plates, the glasswool being preferably so bound by the asbestos threads as to place considerable of the glass-wool between the threads and the plates. This separation is particularly desirable where asbestos :is employed, as this substance tends to promote polarization, while the glass has a tendency to prevent polarization, thus increasing the working voltage and general efficiency of the battery. Asbestos paper or asbestos cloth, for the reason above pointed out, is impractical for use as a separator.

I will explain my invention more fully by reference to the accompanying drawings, in which- Figure I is a side elevation of a separator, preferably in the form of an envelop designed to contain a battery-plate. Fig. 2 is a sectional elevation on line 2 2 of Fig. 3, the binding-threads being preferably concealed on the interior. Fig. 3 is a sectional View on line 3 3 of Fig. I, a battery-plate being indicated in position.

Like parts are indicated by similar characl ters of reference throughout the different gures.

The mass of wool or, composed of glass fibers which are preferably long, may be somewhat in the physical form and arrangement of cotton-batting, the fibers having no definite arrangement to promote the effectiveness of the mass as a lter without impairing the circulating characteristic thereof. Each separator is preferably individually formed by selecting a mass of the required area and passing threads b through the same', preferably in right-angular directions, the thread being also disposed to form a selvage around the border to prevent the same from being unraveled. These threads are preferably passed through the glass fabric in a manner to present but little or none of their surfaces to the battery-plates. In actual practice very little, if any, of these threads need appear upon the surface of the separator that is adjacent to the battery-plate, as the fibers of' the glass-wool are preferably disposed in so many promiscuous directions as to be readily bound together without the necessity of the threads passing entirely through the mat.

While I prefer to employ a non-metallic thread in the form of asbestos as the binding agency, I do not Wish to be limited to the means by which the glass fibers are bound together.

I prefer to unite the separators so that each pair will together form an envelop, the separators of each pair being sewed together along the side and bottom margins by means of the binding-thread. I prefer to first place along the meeting edges of the envelop a cord c, preferably of asbestos, having the thickness of the battery-plate, this cord acting as a distance-preserving device to afford a su fiicient space for the entry of the plate, which is disposed completely within the envelop formed by the pair of separators. This cord and the separators are bound together by means of thread e, which is also asbestos. I prefer to unite the separators in pairs in this manner to form envolops, so that the dislodged particles that fall off the edges may accumulate in the bottoms of the envelops and cannot aggregate to short-circuit the battery elements. Moreover, the employment of the separators in the form of envelops enables the placement of the battery-plates any suitable distance apart. Vhen they are located wide apart, so that the adjacent separators cannot cooperate in maintaining the sides of the envelops close to the plates, cords f are preferably Wound about the envelops to maintain the required intimacy of contact.

The separator of my invention is prefer-Y ably formed as an unwoven fabric composed of glass fibers, which fabric I believe to be broadly new with me. There are features of my invention, however, as will be apparent, that may be embodied in separators having other structural characteristics.

I am aware that glass fibers have been woven into mats. By the very nature of the glass fibers, however, large interstices have to be provided between groups of the fibers, as the fibers will not bend at sufficiently sharp angles to form a woven fabric without large interstices. When used as a separator, this structure is objectionable, for the reason that the woven fabric is not a good filtering medium, permitting substances of the battery to pass through the comparatively large interstices, which substances may accumulate and short-circuit or otherwise injure the battery. l have produced a felt formed of glass-wool. By the term felt is meant an unwoven fabric of fibers matted together. By using the glass fibers in an unwoven condition no large interstices need be left inthe separator, as the fibers of the glass-wool need not be bent at sharp angles in the formation of the separator.

While I have herein shown and particuL larly described the preferred embodiment of my invention, it is obvious that changes may loo IIO

readily be made without departing from the form therewith an unwoven fabric, substantially as described.

et. A separator for storage batteries, composed of glass fibers formed into an unwoven fabric.

5. A pair of separators for storage-battery use, made of glass :fibers formed into an un- Woven fabric, the said separators being united to form a container for a battery-plate, substantially as described.

6. A pair of separators for storage-battery use, composed of glass Wool and bindingthreads passed among the fibers of the glass- Wool to form therewith an unwoven fabric, the said separators being united to form a container for 'a battery-plate, substantially as described.

7. A pair of separators for storage-battery use, composed of glass-Wool and bindingthreads of insulating material passed among the fibers of the glass-Wool to form therewith an unWoven fabric, the said separators being united to form a container for a battery-plate, substantially as described.

8. A pair of separators for storage-battery use, made of glass fabric united to form a receiving-envelop for a battery-plate, the bers of the fabric having asbestos threads for binding the same, substantialb7 as described.

9. A separator for storage batteries, composed of glass-Wool having binding-threads passed through the fibers thereof to form the said Wool into an unwoven fabric, fibers of the glass-wool extending to the exterior so as to be interposed between the binding-'threads and the battery-plate to be separatedmhereby the binding-threads are prevented from contacting with the battery-plate, substantially as described.

10. A separator for` storage batteries, composed of glass fibers and binding-threads of different material from the glass fibers passing among the glass fibers to bind and maintain the same in the required shape, substantially as described.

11. A separator for storage batteries, composed of glass fibers and asbestos bindingthreads passing among the glass fibers to bind and maintain the same in the required shape, substantially as described.

12. A separator for storage batteries, composed of unwoven glass fibers and having binding-threads of different materiall from the glass ibers for maintaining the said fibers in shape, substantially as described.

13. A separator for storage batteries, composed of unwoven glass fibers and having binding-threads of insulating material for maintaining the said fibers in shape, substantially as described.

14. A separator for storage batteries, composed of unwoven glass fibers and havin gbinding-threads of asbestos for maintaining the said fibers in shape,substantially as described. In Witness whereof I hereunto subscribe my name this 6th day of August, A. D. 1901.

GEORGE M. WILLIS. Witnesses:

GEORGE L. CRAGG, HERBERT F. OBERGFELL. 

